docs: def to_files(self, array_file, vocab_file):
          """Write the embedding matrix and the vocab to files.
  
          :param (file) array_file: file to write array to
          :param (file) vocab_file: file to write vocab to
          """
          logging.info('Writing array...')
          np.save(array_file, self.array)
          logging.info('Writing vocab...')
          self.vocab.to_file(vocab_file)